Fix Travis CI Python 3.4+ build error
Fix Travis CI Python 3.4+ build error

jxtech/wechatpy,hunter007/wechatpy,messense/wechatpy,zaihui/wechatpy,wechatpy/wechatpy,zaihui/wechatpy,zhaoqz/wechatpy,zhaoqz/wechatpy,cloverstd/wechatpy,cloverstd/wechatpy,hunter007/wechatpy